drivers/hwtracing/coresight/coresight-replicator.c

   1 /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
   2  *
   3  * Description: CoreSight Replicator driver
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 and
   7  * only version 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/device.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/io.h>
  19 #include <linux/err.h>
  20 #include <linux/slab.h>
  21 #include <linux/pm_runtime.h>
  22 #include <linux/clk.h>
  23 #include <linux/of.h>
  24 #include <linux/coresight.h>
  25
  26 #include "coresight-priv.h"
  27
  28 /**
  29  * struct replicator_drvdata - specifics associated to a replicator component
  30  * @dev:        the device entity associated with this component
  31  * @atclk:      optional clock for the core parts of the replicator.
  32  * @csdev:      component vitals needed by the framework
  33  */
  34 struct replicator_drvdata {
  35         struct device           *dev;
  36         struct clk              *atclk;
  37         struct coresight_device *csdev;
  38 };
  39
  40 static int replicator_enable(struct coresight_device *csdev, int inport,
  41                              int outport)
  42 {
  43         struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  44
  45         dev_info(drvdata->dev, "REPLICATOR enabled\n");
  46         return 0;
  47 }
  48
  49 static void replicator_disable(struct coresight_device *csdev, int inport,
  50                                int outport)
  51 {
  52         struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  53
  54         dev_info(drvdata->dev, "REPLICATOR disabled\n");
  55 }
  56
  57 static const struct coresight_ops_link replicator_link_ops = {
  58         .enable         = replicator_enable,
  59         .disable        = replicator_disable,
  60 };
  61
  62 static const struct coresight_ops replicator_cs_ops = {
  63         .link_ops       = &replicator_link_ops,
  64 };
  65
  66 static int replicator_probe(struct platform_device *pdev)
  67 {
  68         int ret;
  69         struct device *dev = &pdev->dev;
  70         struct coresight_platform_data *pdata = NULL;
  71         struct replicator_drvdata *drvdata;
  72         struct coresight_desc *desc;
  73         struct device_node *np = pdev->dev.of_node;
  74
  75         if (np) {
  76                 pdata = of_get_coresight_platform_data(dev, np);
  77                 if (IS_ERR(pdata))
  78                         return PTR_ERR(pdata);
  79                 pdev->dev.platform_data = pdata;
  80         }
  81
  82         drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
  83         if (!drvdata)
  84                 return -ENOMEM;
  85
  86         drvdata->dev = &pdev->dev;
  87         drvdata->atclk = devm_clk_get(&pdev->dev, "atclk"); /* optional */
  88         if (!IS_ERR(drvdata->atclk)) {
  89                 ret = clk_prepare_enable(drvdata->atclk);
  90                 if (ret)
  91                         return ret;
  92         }
  93         pm_runtime_get_noresume(&pdev->dev);
  94         pm_runtime_set_active(&pdev->dev);
  95         pm_runtime_enable(&pdev->dev);
  96         platform_set_drvdata(pdev, drvdata);
  97
  98         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
  99         if (!desc) {
 100                 ret = -ENOMEM;
 101                 goto out_disable_pm;
 102         }
 103
 104         desc->type = CORESIGHT_DEV_TYPE_LINK;
 105         desc->subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_SPLIT;
 106         desc->ops = &replicator_cs_ops;
 107         desc->pdata = pdev->dev.platform_data;
 108         desc->dev = &pdev->dev;
 109         drvdata->csdev = coresight_register(desc);
 110         if (IS_ERR(drvdata->csdev)) {
 111                 ret = PTR_ERR(drvdata->csdev);
 112                 goto out_disable_pm;
 113         }
 114
 115         pm_runtime_put(&pdev->dev);
 116
 117         return 0;
 118
 119 out_disable_pm:
 120         if (!IS_ERR(drvdata->atclk))
 121                 clk_disable_unprepare(drvdata->atclk);
 122         pm_runtime_put_noidle(&pdev->dev);
 123         pm_runtime_disable(&pdev->dev);
 124
 125         return ret;
 126 }
 127
 128 #ifdef CONFIG_PM
 129 static int replicator_runtime_suspend(struct device *dev)
 130 {
 131         struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
 132
 133         if (drvdata && !IS_ERR(drvdata->atclk))
 134                 clk_disable_unprepare(drvdata->atclk);
 135
 136         return 0;
 137 }
 138
 139 static int replicator_runtime_resume(struct device *dev)
 140 {
 141         struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
 142
 143         if (drvdata && !IS_ERR(drvdata->atclk))
 144                 clk_prepare_enable(drvdata->atclk);
 145
 146         return 0;
 147 }
 148 #endif
 149
 150 static const struct dev_pm_ops replicator_dev_pm_ops = {
 151         SET_RUNTIME_PM_OPS(replicator_runtime_suspend,
 152                            replicator_runtime_resume, NULL)
 153 };
 154
 155 static const struct of_device_id replicator_match[] = {
 156         {.compatible = "arm,coresight-replicator"},
 157         {}
 158 };
 159
 160 static struct platform_driver replicator_driver = {
 161         .probe          = replicator_probe,
 162         .driver         = {
 163                 .name   = "coresight-replicator",
 164                 .of_match_table = replicator_match,
 165                 .pm     = &replicator_dev_pm_ops,
 166                 .suppress_bind_attrs = true,
 167         },
 168 };
 169 builtin_platform_driver(replicator_driver);